Typewriters



Oct. 13, 1959 E. ASCOLI 2,908,373

TYPEWRITERS Filed July 14, 1958 a 2"- 7 H H Y I 12 S a E INVENTOR ENZOASCOL) ATTORNEY United States Patent TYPEWRITERS .Enzo Ascoli, verd0n,:Switzerland, assignor to Paillard S.A., Sainte-Croix, Vaud,Switzerland, a corporation .-of Switzerland Application July-14, 1958,Serial No. 748,496 Claims priority, applicationSwitzerland August 26,1957 'S-Ciaims. (Cl. 197-139 ""This invention relates to a pageendindicator for ofiice machines, more particularly typewriters.

'Machin'es utilizing electric page end indicators are generallyknown andmay be-divided into two groups; (a) :those'using current supplied byelectric battery cells .and4(-b) thosewusingthe current from an outletof a commercial sourceof supply. The first group has the disadvantages.of' the ready exhaustibility of the energy of the .cells .and thenecessity of frequently replacing them. Machinesof the .second'group mayalso be divided into .two sub-groups; namely, those of .the type inwhich the electric signalpersi'sts during the typingof the last line,and those in whichthe electric signal is only momentary. The first typenecessitates contact means which are en- .:gaged during :the entiresliding movement of the carriage :and have {the disadvantages that; whenparticles of foreign matter lodgebetween the sliding surfaces, thecurrent to the indicator lamp is interrupted and caused to flicker;

andzalso, .that due to wear of the sliding contacting surhaving a shaftand whichis responsive'to movement of v the carriage .inan .escapementdirection, said drum connected with the carriage by a conductive metalband which is a part of the electrical circuit of the apparatus, whilethe shaft or spindle has a line engagement with a blade in the remainderof the circuit.

A further object of the invention is to provide a page end indicatorutilizing a commercial source of current to energize the signal lamp,and, wherein, the construction is such that both sections of thecarriage may be readily removed or detached from the frame of themachine by simply releasing the fastenings connecting the fixed part ofthe carriage with the frame. In other words, since the drum is mountedon the fixed part of the carriage, the removal of the two-part carriagemakes it possible also to lift the shaft out of engagement with a singleresilient wiper type blade which is connected to a transformer feedingoif a commercial line.

In the accompanying drawing is shown diagrammatically and by way ofexample, one form of construction of the subject of the invention. Thetypewriter shown in the drawing comprises, in the known manner, aframework 1, a carriage constituted by a stationary part 2 detachablyconnected to said framework by fastenings 2a and a movable part 3, saidlatter carrying a platen 4. A drum 5 turning about a spindle 6 carriedby a bearing bracket 7 applies a traction on the movable part 3 of thecarriage through the medium of a metal band for moving said carriage inan escapement direction. One end of said band is secured, by means of aterminal rivet 9, to a plug 10 secured to the carriage 3. The plug 10 isof insulating material, so that the band 8'is insulated .electricallyfrom the carriage. The other end of the band 8is attached to the drum 5.As will be seen, the bracket 7 'is' secured to the stationary part 2 ofthe carriage throughrthe medium of stays .11 and 12 of insulating ma- 14, is secured to the movable carriage 3, through the medium ofinsulating cross-pieces 15 and 16, and cooperates with the ring 13. Saidblade 14 is connected,

through the medium of a conductor 17, to the band 8.

Another -flat spring contact blade 18, secured to the framework 1through the medium of insulating stays 19 and 20, has a wipingengagement With the shaft or spindle 6. Said blade 18 is connectedthrough the medium of 'an-indicating device constituted by a signal lamp21, to one of the ends ofa secondary winding 22b of a transformer 22,the other end of the secondary winding 22b is connected to theframework 1. The primary winding 22:! of the transformer 22 is connectedto the electric supply network.

The machine above-described with its indicator device for the end of thepage, functions in the following manner:

Before'the introduction of a sheet of paper (the case shown inthe-drawing), the blade 14 is in contact with secondary winding'22b. Thesignallamp 21 is therefore illuminated.

The introduction ,of a sheet of paper into the typewriter, in such amanner that it passes between the ring1 3 .andrthe'leaf-springcontact14, has as a consequence the rupture-of the ele'ctriccircuit, so thatthe l-amp21 isextinguished. It remains extinguished whilst the sheetseparates the blade 14 from the ring 13 and re-lights when the loweredge of the sheet has passed under the blade 14, whereby the electriccircuit is closed. The blade 14 is placed in such a manner that there-establishment of the circuit takes place when the last line is to betyped.

As will be seen from the foregoing, the indicator device of thetypewriter according to the invention permits'of obtaining an electricsignal indicating the end of the page, said signal persisting during thetyping of the last line (and the following ones if it is desired tocontinue) Without it being necessary for a contact to slide along theentire length of the carriage.

The existence of the elastic contact 18 co-operating with the spindle 6of the drum 5 allows of an easy changing of the carriage.

I claim:

1. A page end indicator for the platen of a typewriter having a frame,comprising, in combination, a carriage including a movable part and apart detachably fixed relative to the typewriter frame, a platenrotatably mounted on the movable part of the carriage, a ring contact onthe platen, a leaf spring contact insulatingly mounted on the movablepart of the carriage and normally biased for engagement with said ringcontact and disengageable therefrom by application of a sheet of paperon the platen to separate said contacts, a conductive terminalinsulatingly mounted on and secured to the end of a 3 7 the movable partof the carriage opposite the leaf spring, a conductive metal bandconnected at one end to said terminal, a rotatable conductive drum aboutwhose periphery the other end of the band is wound when the movable partof the carriage moves in the direction of escapement, a shaft on saiddrum and an electrical circuit including a signal lamp and a conductormaking tangent contact with said shaft.

2. A page end indicator for the platen of a typewriter having a frame,comprising, in combination, a carriage including a movable part and apart fixed relative to the typewriter frame, a platen rotatably mountedon the movable part of the carriage, a ring contact on the platen, a

leaf spring contact insulatingly mounted on the movable part of thecarriage and normally biased for engagement with said ring contact anddisengageable therefrom by application of a sheet of paper on the platento separate said contacts, a conductive terminal insulatingly mounted onand secured to the end of the movable part of the carriage, a conductorbetween said leaf spring contact on the movable'part of the carriage andsaid terminal, a conductive drum and shaft, a flexible conductiveelement connecting said terminal and the'periphery of said drum to movethe carriage in an escapement direction, a conductive bearing bracketfor said shaft, insulating means connecting the bracket with the part ofthe carriage fixed to the typewriter frame, and a conductor insulatedfrom and carried by the frame of the typewriter and in tangentialengagement with the drum shaft, said blade being part of a circuitcommunicating with a source of electrical energy and including a signallamp adapted to glow when the said ring contact and leaf spring contactare engaged.

3. A page end indicator for sheets applied to a platen rotatablysupported on the part of a carriage responsive to movement in anescapement direction in relation to the fixed part of the carriagedetachably mounted on the frame of the machine, a contact ring on theplaten, a leaf spring on the movable part of the carriage andrnormallybiased to engage the ring except when a sheet is interposed between itand the leaf spring, a conductive terminal mounted in insulation on saidmovable part of the carriage and conductively connected to the said leafspring,

- a conductive drum and shaft having an insulated mount- -'-ing on thefixed part of the carriage, a metal band connected at one end to saidconductive terminal and its other end coiled about the periphery of saiddrum as the.

i carriage moves in said escapement direction, a spring contact bladehaving one end mounted on an insulating 'support on the frame and itsother end making a line contact with said shaft, whereby, the entirecarriage can be detached from and replaced on the frame, a transformerwithin the frame having its primary winding adapted for connection witha source of commercial electrical energy and its secondary winding incircuit with said contact blade and the frame of the machine, and asignal lamp in the secondary winding circuit. A

4. A page end indicator according to claim 3, wherein, the conductiveterminal is mounted in the shank of an insulating plug having a headexposed at one end of the movable part of the carriage. i

5. A page end indicator for the platen of a typewriter having a frame,comprising, in combination, a carriage including a movable part and apart fixed relative to the typewriter frame, a platen rotatably mountedon the movable part of the carriage, a ring contact on the platen, aleaf spring contact insulatingly mounted on the movable part of thecarriage and normally biased for engagement with said ring contact anddisengageable therefrom by application of a sheet of paper on the platento separate said contacts, a conductive terminal insulatingly mounted onand secured to the end of the movable part of the carriage opposite theleaf spring contact, a conductor between said leaf spring contact andsaid terminal, a conductive drum and shaft, a metal band connected tosaid terminal and to the periphery of said drum for shifting saidmovable part of the carriage in an escapement direc- 'tion, a conductivebearing bracket for said shaft, insulating means connecting the bracketwith the part of the carriage fixed to the typewriter frame, and a leafspring blade having an insulating mounting on the frame of thetypewriter and in engagement with the drum shaft, said blade beingincluded in a transformer circuit communicating with a source ofelectrical energy and-including a signal lamp in one leg of the circuitand adapted to glow when the said ring contact on the platen and itsrelated leaf spring contact are engaged because of the lack ofseparation by said sheet of paper.

References Cited in the file of this patent UNITED STATES PATENTS

